高新技术产业分类目录:1+1/1+2+1/1+2+3+1/1+2+3+4+.........1/1+2+3+........+1000

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1/1*7+1/7*13+1/13*19+1/19*25+1/25*31+1/31*37
写过程
说原因

1+1/1+2+1/1+2+3+1/1+2+3+4+.........1/1+2+3+........+1000
=1+1/[(1+2)×2÷2]+1/[(1+3)×3÷2]+1/[(1+4)×4÷2]+........1/[(1+1000)×1000÷2]
=1+2/(1+2)×2+2/(1+3)×3+2/(1+4)×4+........2/(1+1000)×1000
=1+2×(1/2-1/3+1/3-1/4+1/4-1/5+.......+1/1000-1/1001)
=1+2×1/1001
=1又2/1001

1/1*7+1/7*13+1/13*19+1/19*25+1/25*31+1/31*37
=1/6×(1-1/7+1/7-1/13+1/13-1/19+1/19-1/25+1/25-1/31+1/31-1/37)
=1/6×(1-1/37)
=6/37

1/1*7=1/6(1-1/7)
1/7*13=1/6(1/7-1/13)
……
……
1/n*(n+6)=1/6[(1/n)-1/(n+6)]

1/1*7+1/7*13+1/13*19+1/19*25+1/25*31+1/31*37
=1/6(1-1/37)=6/37

1+1/1+2+1/1+2+3+1/1+2+3+4+.........1/1+2+3+........+1000
=1+1/[(1+2)×2÷2]+1/[(1+3)×3÷2]+1/[(1+4)×4÷2]+........1/[(1+1000)×1000÷2]
=1+2/(1+2)×2+2/(1+3)×3+2/(1+4)×4+........2/(1+1000)×1000
=1+2×(1/2-1/3+1/3-1/4+1/4-1/5+.......+1/1000-1/1001)
=1+2×1/1001
=1又2/1001

1/1*7+1/7*13+1/13*19+1/19*25+1/25*31+1/31*37
=1/6×(1-1/7+1/7-1/13+1/13-1/19+1/19-1/25+1/25-1/31+1/31-1/37)
=1/6×(1-1/37)
=6/37

+1/1+2+1/1+2+3+1/1+2+3+4+.........1/1+2+3+........+1000
=1+1/[(1+2)×2÷2]+1/[(1+3)×3÷2]+1/[(1+4)×4÷2]+........1/[(1+1000)×1000÷2]
=1+2/(1+2)×2+2/(1+3)×3+2/(1+4)×4+........2/(1+1000)×1000
=1+2×(1/2-1/3+1/3-1/4+1/4-1/5+.......+1/1000-1/1001)
=1+2×1/1001
=1又2/1001

1/1*7+1/7*13+1/13*19+1/19*25+1/25*31+1/31*37
=1/6×(1-1/7+1/7-1/13+1/13-1/19+1/19-1/25+1/25-1/31+1/31-1/37)
=1/6×(1-1/37)
=6/37

我也看不懂
1+1/1+2+1/1+2+3+1/1+2+3+4+.........1/1+2+3+........+1000(这个能看懂)但1000后还要+1啊!
1000次,用前面的依次加后面的,如:1+1000,2+999,3+998,4+997。。。。。这样一共加500次,1000除2(前后相加,一半)所以1001乘以500等于500500。
后面的就不会了!

rrr